Change AGM times to match those in the text (#543)

* Change AGM times to match those in the text

The event text and newsletter both mention a 1 PM ET start. This PR
updates the event metadata to match that.

* Update 2021-12-AGM.md

@lparsons I changed the expiry date to be the day after. This ensures the event will still appear as current on the events list on Dec 3. Otherwise it can disappear from current events before the event is over if website is updated.

Co-authored-by: Chris Hill <cnh@mit.edu>

_events/2021/2021-12-AGM.md

@@ -2,14 +2,14 @@
 title: US-RSE Annual General Meeting 2021
 subtitle: All Member US-RSE Event
 location: Online via Zoom
-expires: 2021-12-03
+expires: 2021-12-04
 event_date: "December 3, 2021"
 layout: event
 repeated: false
 category: virtual-workshop
 time:
-    - - start: 2021-12-03T16:00:00Z
-        end: 2021-12-03T18:00:00Z
+    - - start: 2021-12-03T18:00:00Z
+        end: 2021-12-03T20:00:00Z
 ---
 
 The second US-RSE Association Annual General Meeting (AGM) will take place on Friday December 3, 2021 from 1-3pm ET.